Northern Ireland's Conor Washington (left) celebrates scoring his side's first goal of the game with team mates Oliver Norwood and Jonathan Evans during an International Friendly at Windsor Park, Belfast. PA

BELFAST, NORTHERN IRELAND - MARCH 28: Roy Carroll of Northern Ireland saves a penalty from Novakovic Milivoje of Slovenia during the international friendly between Northern Ireland and Slovenia at Windsor Park on March 28, 2016 in Belfast, Northern Ireland. (Photo by Charles McQuillan/Getty Images)

Northern Ireland's Conor Washington celebrates scoring his side's first goal of the game during an International Friendly at Windsor Park, Belfast. PRESS ASSOCIATION Photo. Picture date: Monday March 28, 2016. See PA story SOCCER N Ireland. Photo credit should read: Niall Carson/PA Wire.

Northern Ireland fans during the 14th minute stand up and applaud in respect of Johan Cruyff who died recently during an International Friendly at Windsor Park, Belfast. PRESS ASSOCIATION Photo. Picture date: Monday March 28, 2016. See PA story SOCCER N Ireland. Photo credit should read: Liam McBurney/PA Wire.

Northern Ireland fans observe a minutes silent in respect to Sean McGrotty, 49, his sons Mark, 12, and Evan, 8, his mother-in-law Ruth Daniels, 59, and Ms Daniels' daughter Jodie Lee Daniels, who was 14 who died in Buncrana, Co. Donegal before an International Friendly at Windsor Park, Belfast. PA

Northern Ireland fans during the 14th minute stand up and applaud in respect of Johan Cruyff who died recently during an International Friendly at Windsor Park, Belfast. PRESS ASSOCIATION Photo. Picture date: Monday March 28, 2016. See PA story SOCCER N Ireland. Photo credit should read: Liam McBurney/PA Wire.

Northern Ireland's Conor Washington (left) celebrates scoring his side's first goal of the game with team mates during an International Friendly at Windsor Park, Belfast. PRESS ASSOCIATION Photo. Picture date: Monday March 28, 2016. See PA story SOCCER N Ireland. Photo credit should read: Niall Carson/PA Wire.

BELFAST, NORTHERN IRELAND - MARCH 28: Conor Washington (L) of Northern Ireland celebrates after scoring during the international friendly between Northern Ireland and Slovenia at Windsor Park on March 28, 2016 in Belfast, Northern Ireland. (Photo by Charles McQuillan/Getty Images)

Northern Ireland's Stephen Davis (left) reacts to a challenge from Slovenia's Jokic Bojan during an International Friendly at Windsor Park, Belfast. PA

BELFAST, NORTHERN IRELAND - MARCH 28: Jamie Ward (R) of Northern Ireland and Krhin Rene (L) of Slovenia during the international friendly between Northern Ireland and Slovenia at Windsor Park on March 28, 2016 in Belfast, Northern Ireland. (Photo by Charles McQuillan/Getty Images)

BELFAST, NORTHERN IRELAND - MARCH 28: Jamie Ward (L) of Northern Ireland and Krhin Rene (R) of Slovenia during the international friendly between Northern Ireland and Slovenia at Windsor Park on March 28, 2016 in Belfast, Northern Ireland. (Photo by Charles McQuillan/Getty Images)

Northern Ireland's defender Paddy McNair (R) vies with Slovenia's midfielder Benjamin Verbic during the international friendly football match between Northern Ireland and Slovenia at the National Football Stadium at Windsor Park in Belfast on March 28, 2016. / AFP PHOTO / PAUL FAITHPAUL FAITH/AFP/Getty Images

Northern Ireland's defender Paddy McNair (R) vies with Slovenia's midfielder Benjamin Verbic during the international friendly football match between Northern Ireland and Slovenia at the National Football Stadium at Windsor Park in Belfast on March 28, 2016. / AFP PHOTO / PAUL FAITHPAUL FAITH/AFP/Getty Images

Northern Ireland fans in the stands show their support during an International Friendly at Windsor Park, Belfast. PRESS ASSOCIATION Photo. Picture date: Monday March 28, 2016. See PA story SOCCER N Ireland. Photo credit should read: Niall Carson/PA Wire.

Northern Ireland players line up with mascots to sing their country's national Anthem prior to kick off during an International Friendly at Windsor Park, Belfast. PRESS ASSOCIATION Photo. Picture date: Monday March 28, 2016. See PA story SOCCER N Ireland. Photo credit should read: Niall Carson/PA Wire.